1. Field of the Invention
The present invention relates to a heat pump system having a small-size heat storage section for storing heat by decomposing or separating a heat storage material by heating.
2. Related Art of the Invention
A conventional heat pump system having a heat storage section (for example, Japanese Patent Laid-Open No. 11-193958) utilizes a thermal output from a high-temperature and high-pressure refrigerant discharged from a compressor, and stores a large quantity of hot water in a hot water storage tank while repeating a cycle for raising temperature by circulating hot water in the hot water storage tank.
Also, a regenerative heat pump system (for example, Japanese Patent Laid-Open No. 5-288425), which is a combination of a regenerative heat pump and a compression heat pump, utilizes a thermal output from a refrigerant as heat for reaction, and chemically stores heat by storing a substance generated by this reaction.
The entire disclosures of Japanese Patent Laid-Open No. 11-193958 and Japanese Patent Laid-Open No. 5-288425 are incorporated herein by reference in their entirety.
In the above-described conventional heat pump system having a heat storage section, a large-capacity hot water storage tank is required. Therefore, there arise problems regarding installation and workability such as installation space, weight of hot water storage tank, and load-carrying capacity of installation portion.
Also, in the conventional regenerative heat pump system, the thermal output from a refrigerant having a temperature lower than the reaction temperature is not utilized effectively, which poses a problem in that it is difficult to secure high COP.
Also, in the case where a gaseous product is generated in the reaction, it is necessary to liquefy the product or to form a compound with other substances or an adsorbent in order to reduce the storage space. In this case, there arises a problem in that the generated heat of reaction cannot be recovered sufficiently.
Also, there arises a problem in that when heat is taken out by utilizing exothermic reaction, the thermal output cannot be provided in a moment because of the heat capacity of a reactor vessel. Further, there arises a problem in that power is consumed to supply a reactant at this time, or heat cannot be supplied with high energy efficiency.
Further, in the case where a reactant for carrying out exothermic reaction is absent because of high heat demands, there arises a problem in that the thermal output cannot be provided.